Author + information
- Received December 17, 2004
- Accepted January 11, 2005
- Published online August 16, 2005.
- Philippe Garot, MD⁎,⁎ (, )
- Thierry Lefèvre, MD†,
- Michael Savage, MD‡,
- Yves Louvard, MD⁎,
- William R. Bamlet, MS∥,
- James T. Willerson, MD§,
- Marie-Claude Morice, MD† and
- David R. Holmes Jr, MD∥
- ↵⁎Reprint requests and correspondence:
Dr. Philippe Garot, Institut Cardio-vasculaire Paris Sud, Hôpital Privè Claude Galien, 20 Route de Boussy, 91480 Quincy, France
Objectives The aim of this research was to determine the influence of bifurcation lesions on the outcome of patients undergoing percutaneous coronary intervention (PCI) in the recent era.
Background The treatment of bifurcation lesions by PCI has been associated with an increased complication rate. Whether recent improvements of interventional practice have translated into improved outcomes in this patient subgroup is unknown.
Methods The 11,482 patients enrolled in the Prevention of Restenosis with Tranilast and its Outcomes (PRESTO) were stratified according to the presence (n = 1,412) or absence (n = 10,068) of at least one bifurcation lesion treated by PCI. Baseline characteristics and outcome of patients undergoing PCI for bifurcation lesions were compared to those of patients treated for nonbifurcation lesions.
Results Patients treated for bifurcation lesions were less likely to have prior myocardial infarction (MI), prior coronary artery bypass graft surgery, and had a higher proportion of current stable angina (p < 0.01 for all comparisons). Bifurcation lesions involved more frequently the left anterior descending coronary artery and were more complex (angulated, eccentric, ostial, and tortuous) than nonbifurcation lesions. Percutaneous coronary intervention of bifurcation lesions was characterized by less frequent stent implantation (71% vs. 80%); PCI of bifurcation lesions was associated with an increased rate of combined end point death/MI/target vessel revascularization (TVR) at nine months (18% vs. 15%, p = 0.002) because of increased rates of TVR (17% vs. 14%, p < 0.001), whereas death (1%) and MI (1%) were not different between groups.
Conclusions Percutaneous coronary intervention of bifurcation lesions is associated with higher TVR at follow-up. However, the risk of death, MI, death/MI was similar in patients treated for bifurcation or nonbifurcation lesions.
The success rate of bifurcation lesion percutaneous coronary interventions (PCI) has been reported to be lower with higher incidence of procedural and periprocedural complications, including procedural-induced myocardial infarction (MI) and emergent coronary artery bypass graft (CABG) surgery compared with nonbifurcation lesions (1,2). In addition, there are increased major adverse cardiac events (MACE) at one-year follow-up with reduced event-free (MI, CABG, and repeat coronary angioplasty) survival rates in patients treated by PCI for bifurcation lesions compared with nonbifurcation lesions (1). However, this finding has not been consistently observed in unselected patients with bifurcation lesions undergoing PCI (2).
The Prevention of Restenosis with Tranilast and its Outcomes (PRESTO) trial was designed to test the hypothesis that tranilast would reduce restenosis in patients undergoing PCI (3). Although the trial was negative (4), it is the largest restenosis trial performed, with broad inclusion and limited exclusion criteria, and therefore affords a look at contemporary interventional practice. Using data from the PRESTO trial, we sought to evaluate the clinical and angiographic patient outcomes of bifurcation lesions treated by PCI compared with those of nonbifurcation lesions.
The study design and outcome of the PRESTO trial have been reported elsewhere (3). Briefly, the trial was a double-blind, randomized (1:1:1:1:1) placebo-controlled trial of patients undergoing successful PCI of at least one significant lesion. Procedural success was defined by <50% angiographic residual stenosis without death, MI, or need for CABG surgery before the first dose of study medication. Patients were randomly assigned to one of five arms: 1) placebo for three months twice a day; 2) 300 mg tranilast orally twice a day for three months; 3) 450 mg tranilast orally twice a day for three months; 4) 300 mg tranilast orally twice a day for one month followed by two months of placebo; and 5) 450 mg tranilast orally twice a day for one month followed by two months of placebo. The primary end point of the study was the first occurrence of death, MI, or ischemia-driven target vessel revascularization (TVR) within nine months of the PCI. For the present analysis, patients enrolled in the PRESTO trial were stratified according to presence or absence of at least one bifurcation lesion treated by PCI on the qualifying PCI. A bifurcation lesion was defined as a coronary stenosis involving a side branch ≥2.0 mm in reference diameter.
All baseline characteristics are reported separately for patients treated by PCI for bifurcation or nonbifurcation lesions, with continuous variables reported as mean ± 1 SD and categorical variables reported as counts and percentages. Differences in baseline patient characteristics were assessed by using two-sample ttests for continuous variables and chi-square tests for categorical variables. Logistic regression models were established to investigate independent predictors of MACE (death, MI, ischemia-driven TVR) and TVR in patients with bifurcation lesions. These models were adjusted for age, gender, study center, and tranilast treatment group. Clinical and procedural characteristics with p < 0.10 were entered in the models. Odds ratio with corresponding 95% confidence intervals are reported.
The primary end point of the present analysis was to compare outcomes between patients undergoing PCI of at least one bifurcation lesion and those with nonbifurcation lesions nine months after the index procedure. The clinical outcome was defined as the composite end point of death, MI, or TVR. The secondary clinical end point was to compare outcome defined by the same composite of events in the patients stratified as introduced earlier at 30-day follow-up. Additional analyses considered each component of the combined end point separately at 9 months and 30 days after the index PCI.
A protocol-driven angiography substudy was prespecified in the main PRESTO trial and included 2,018 patients. For this analysis, angiographic outcomes were compared between patients undergoing PCI for at least one bifurcation lesion and for nonbifurcation lesions. At initial coronary angiography, reference diameter, minimal luminal diameter, and diameter stenosis were assessed in patients with bifurcation and nonbifurcation lesions. The acute gain was calculated as the difference between post- and pre-PCI minimal luminal diameter. Repeat coronary angiography in the angiographic substudy was scheduled at nine-month follow-up, and the late loss and late loss index were compared in patients with bifurcation and nonbifurcation lesions. Angiographic restenosis was defined as >50% narrowing in the treated segment (worst stenosed lesion). The angiograms were analyzed by two laboratories using the cardiovascular measurement system (Medis Medical Imaging System, Leiden, the Netherlands) for quantitative measurements.
A total of 1,412 patients treated by PCI for at least one bifurcation lesion (12.3% of the whole study population) and 10,068 patients treated for nonbifurcation lesions were identified in the PRESTO database. Compared with patients treated by PCI for nonbifurcation lesions, patients with bifurcation lesions had similar incidence of diabetes, dyslipidemia, and current smoking. Patients with bifurcation lesions were less likely to have a history of MI (34% vs. 39%, p < 0.001), less likely to have prior CABG surgery (11% vs. 14%, p = 0.002), and evidence of peripheral vascular disease (4% vs. 6%, p = 0.010), but more likely to have current stable angina (44% vs. 41%, p = 0.009), whereas ejection fraction, a history of congestive heart failure, a history of prior acute coronary syndromes, prior PCI, and prior cerebrovascular events were comparable between groups (Table 1).
Compared with patients undergoing PCI for nonbifurcation lesions, patients treated for at least one bifurcation lesion were more likely to be treated in the left anterior descending artery (Table 2),had worse angiographic lesion characteristics including angulation >45° (15% vs. 8%, p < 0.001), de novo lesions (88% vs. 85%, p = 0.020), eccentric lesions (52% vs. 48%, p = 0.001), ostial lesions (15% vs. 6%, p < 0.001), and tortuous lesions (9% vs. 8%, p = 0.023). Stenting was less frequently used in patients with bifurcation lesions (71% vs. 80%, p < 0.001), but coronary atherectomy was more frequently used in these patients (Table 3).Patients with bifurcation lesions had 1.8 ± 0.8 lesions treated versus 1.4 ± 0.6 for patients with nonbifurcation lesions (p < 0.001), were more likely to have higher percent stenosis both before (88.4 ± 9.4% vs. 87.2 ± 10.4%, p < 0.001) and after PCI (7.7 ± 12.6% vs. 5.1 ± 9.6%, p < 0.001), as well as higher PCI-induced grades 1 to 4 dissection (16% vs. 13%, p = 0.005), thus leading to a higher rate of failed PCI (1.4% vs. 0.4% for patients treated for nonbifurcation lesions, p < 0.001).
MACE during follow-up
Thirty-day adverse event rate was relatively low, with similar low incidences of death (<1%, p = 0.29), MI (<1%, p = 0.57), TVR (1%, p = 0.11), and need for repeat coronary revascularization (1%, p = 0.39) in patients undergoing PCI for bifurcation or nonbifurcation lesions. During subsequent follow-up, the combined end point death/MI/TVR was higher in patients treated for bifurcation lesions (compared with patients treated for nonbifurcation lesions) because of higher TVR (17% vs. 14%, p < 0.001) and despite similar rates of death (1%), MI (1%), and death/MI (2%) (Table 4).Additionally, patients with bifurcation lesions had a higher rate of re-intervention by PTCA or CABG surgery (21% vs. 17%, p = 0.001) at nine-month follow-up.
Among the PRESTO patients enrolled in the angiographic substudy (n = 2,018), the postprocedural percent diameter stenosis was significantly higher in patients treated by PCI for at least one bifurcation lesion with subsequent higher acute gain in patients with nonbifurcation lesions. However, the late loss (1.0 ± 0.8 vs. 1.0 ± 0.8, p = 0.96) and loss index (0.5 ± 0.5 vs. 0.5 ± 0.6, p = 0.44) were not different in patients with bifurcation or nonbifurcation lesions (Table 5).Although the late loss was not different between groups, the binary restenosis rate was 28% for patients treated for bifurcation lesions and 22% for patients treated for nonbifurcation lesions (p = 0.022). Subsequent analysis of the group of patients treated for at least one bifurcation lesion demonstrated that patients undergoing angiographic follow-up had higher rates of TVR (21% vs. 16%, p = 0.028), repeat PTCA (26% vs. 13%, p < 0.001), and PTCA/CABG (30% vs. 17%, p < 0.001) compared with patients in whom the need for repeat revascularization was driven by documented ischemia (spontaneous or induced by noninvasive tests) (Table 6).
Predictors of MACE and TVR
After adjusting for age, gender, study center, and tranilast treatment group in patients treated for bifurcation lesions, lesions treated per patient, diabetes mellitus, history of prior CABG, and transient ischemic attacks, as well as clinical presentation (angina status) were independently associated with an increased likelihood of MACE and TVR at follow-up. Conversely, use of stents and treatment of de novo lesions were associated with lower rates of MACE, whereas treatment of restenosis lesions was an independent predictor of TVR at follow-up (Table 7).
In recent interventional practice, PCI of a bifurcation lesion is not associated with increased MI/death rates at 30-day and 9-month follow-up. Compared with patients treated for nonbifurcation lesions, an increased rate of TVR and reintervention is seen. The increase in TVR is, in part, the result of the so-called “oculo-stenotic reflex,” as patients in the angiographic study had more frequent TVR compared with patients followed only clinically. This bias may influence the management and outcome of patients undergoing PCI, as previously described in the Belgium and Netherlands Stent (Benestent II) study (5). Additionally, patients treated for bifurcation lesions had significantly more lesions treated (1.8 vs. 1.4 per patient, p < 0.001), which may obviously have a significant impact on the rate of reinterventions.
Bifurcation lesions, PCI, and outcomes
Treatment of bifurcation lesions has been challenging. Indeed, specific difficulties involving access to the side branch and the snowplow effect phenomenon have been identified even before the era of near-universal stenting. The procedural success rate was consequently lower compared with that of nonbifurcation lesions (2,6–10). As a consequence, patients with bifurcation lesions were preferentially referred to cardiac surgery until the late 1980s, and this strategy remains common in many Western countries. Although superior to that of nonbifurcation lesions (37 of 10,068, 0.4%), the rate of PCI failure was 20 of 1,412 procedures (1.4%) in the study population, which contrasts with the 3% to 13% rates of PCI failure reported in the literature (1,2,6–10). Recently, Singh et al. (11) have reported, using the same PRESTO dataset, that in patients with restenosis on follow-up angiograms, 7% were treated for bifurcation lesions and 5% for nonbifurcation lesions (p = 0.14). In order to avoid data duplication, this analysis was not included in the present paper. Furthermore, the TVR rate was, although statistically higher, modestly increased in patients treated for bifurcation lesions compared to that of patients treated for nonbifurcation lesions (17% vs. 14%, respectively, p < 0.001). Additionally, this result needs to be considered with regard to other obvious procedural characteristics influencing the rate of TVR that were more frequent in patients treated for bifurcation lesions (more lesions treated, more ostial lesions, lower stent use). According to the 13.2% TVR we recently reported in a large prospective cohort (12), we found that the rate of TVR was relatively low in patients treated for bifurcation lesions, close to that of nonbifurcation lesions.
It is noteworthy that the strategy used to treat coronary lesions may obviously influence the outcome of PCI, and this is specifically true in the management of bifurcation lesions. Actually, interventional strategies have been recently developed to facilitate the approach to bifurcation lesions. The main difficulty in evaluating the efficacy of such strategies results from inherent limitations of most published registries including: the small populations of patients reported, the retrospective design of the studies, the variety of lesions types (“true” and “false” bifurcation), and techniques that are usually incompletely or inadequately described. Treatment of bifurcation lesions with debulking techniques (directional and rotational atherectomy) without stenting were variable, and stenting became the standard strategy because of its scaffolding properties with the subsequent reduction of acute complications. The potential benefit of debulking before stenting remains controversial because some nonrandomized studies have suggested that debulking before stenting may be associated with lower restenosis rates (13), whereas other reports suggested that these benefits were obtained at the cost of higher complication rates in patients treated by atherectomy and stenting versus patients treated by stenting alone, including higher rates of postprocedure non–Q-wave MI (14). In the present study, a debulking device (directional or rotational atherectomy) was used more frequently in patients treated for bifurcation lesions (6.6% vs. 4.6% in patients treated for a nonbifurcation lesion), and this could have played a role in the higher rates of PCI-induced dissections and failed procedures observed in patients treated for bifurcation lesions.
The main challenging issue with stenting in bifurcation lesions is to optimize stenting of the main branch while preserving the side branch. To address this issue, data collected from bench test studies proved crucial, allowing the understanding of stent behavior and the effects of empirically implemented strategies (15). In our experience (12), provisional T stenting of the side branch after systematic stenting of the main branch was the strategy associated with the lowest rate of MACE and TVR at follow-up when compared with strategies involving stenting of both main and side branches (Y, V, and T stenting strategies). The use of drug-eluting stents has proven beneficial in dramatically reducing the rates of reintervention in unselected patients with de novo coronary lesions treated by PCI compared with bare metal stents (16). Despite technical improvements in equipment and the experience acquired in many interventionalist centers, stent placement in diabetic patients, long lesions, small vessels, and bifurcation stenoses is associated with a restenosis rate that may exceed 50% (17). The potential effect of drug-eluting stents in decreasing the rates of MACE and reintervention after PCI of bifurcation lesions has been recently published by Colombo et al. (18), who reported an improvement compared with historical controls using bare metal stents with a restenosis rate of 25.7% and a TLR of 8.1% (7 of 86). However, this study showed discrepancies between patients treated with different strategies using sirolimus-eluting stents. Indeed, there was a slight but nonsignificant trend toward higher rates of restenosis in patients treated with systematic side branch stenting (28%) versus patients treated with provisional side branch stenting (18.7%). Overall, these results support a role for the strategy used in the treatment of complex coronary lesions such as bifurcation lesions. This is corroborated by the European Study of the Sirolimus-Eluting Stent in the Treatment of Patients with Long De Novo Lesions in Small Native Coronary Arteries (E-SIRIUS) trial (19) suggesting that optimal outcomes with a potent therapy such as drug-eluting stents are still operator-dependent and validated by the Canadian Study of the Sirolimus-Eluting Stent in the Treatment of Patients with Long De Novo Lesions in Small Native Coronary Arteries (C-SIRIUS) (20) that subtends a potential role of PCI technique itself in different restenosis rates observed in SIRIUS (8.9%), the Randomized Comparison of a Sirolimus-Eluting Stent with a Standard Stent for Coronary Revascularization (RAVEL) (0%), E-SIRIUS (5.9%), and C-SIRIUS (2.3%). More recently, restenosis was reported to be relatively low with sirolimus-eluting stents (7.9% of lesions), occurring mainly in high-risk patients, in-stent, for long lesions, small vessels, and bifurcation lesions (21). In the present study, predictors of MACE and TVR after PCI of bifurcation lesions are consistent with previous reports emphasizing the role of clinical (diabetes mellitus, prior CABG, history of transient ischemic attack, angina status) and procedural characteristics (de novo lesions/restenosis, stents) in increasing MACE rates after PCI of nonbifurcation lesions (22,23).
This is a post-hoc analysis of a prospective, randomized trial, and it has the intrinsic limitations of any retrospective study. However, the study population is a large and contemporary interventional population with relatively complete data and follow-up. Thus, some specific characteristics of bifurcation lesions and their PCI were not described in detail, and their potential impact on the outcome of patients may not have been taken into account in the present analysis.
Compared with nonbifurcation lesions, PCI of bifurcation lesions is associated with higher rates of TVR but similar rates of death and MI at nine months. This higher rate of TVR may be due in part to the “oculo-stenotic” reflex observed in patients undergoing coronary angiography at nine-month follow-up in the angiographic substudy. Further decreases in restenosis rates using drug-eluting stents and optimized strategies dedicated to bifurcation lesions need to be determined in future studies.
GlaxoSmithKline provided financial support for important scientific, but nonproduct-related, publications based on data from the PRESTO trial. The PRESTO trial was supported by grants from GlaxoSmithKline Pharmaceuticals.
- Abbreviations and Acronyms
- coronary artery bypass grafting
- major adverse cardiac events
- myocardial infarction
- Prevention of Restenosis with Tranilast and its Outcomes trial
- Study of the Sirolimus-Eluting Stent in the Treatment of Patients with Long De Novo Lesions in Small Native Coronary Arteries
- target vessel revascularization
- Received December 17, 2004.
- Accepted January 11, 2005.
- American College of Cardiology Foundation
- Al Suwaidi J.,
- Berger P.B.,
- Rihal C.S.,
- et al.
- Holmes D.R. Jr..,
- Savage M.,
- LaBlanche J.M.,
- et al.
- Ruygrok P.N.,
- Melkert R.,
- Morel M.-A.M.,
- et al.
- Singh M.,
- Gersh B.J.,
- McClelland R.L.,
- et al.
- Kokis A.,
- Sengottuvel G.,
- Lefevre T.,
- et al.
- Mercado N.,
- Boersma E.,
- Wijns W.,
- et al.
- Colombo A.,
- Moses J.W.,
- Morice M.C.,
- et al.
- Schampaert E.,
- Cohen E.A.,
- Schlüter M.,
- et al.
- Lemos P.A.,
- Hoye A.,
- Goedhart D.,
- et al.
- Mathew V.,
- Gersh B.J.,
- Williams B.A.,
- et al.